Google has brought online its first cloud data centers in Northern Virginia, the largest data center market in the US and one of the largest in the world, as well as the location of the biggest cloud availability region of Amazon Web Services, whose business Google Cloud Platform is going after with a vengeance (and $10 billion in annual data center spend).

While AWS remains far ahead its rivals in terms of market share, Microsoft, Google, IBM, Alibaba, and Oracle all reported faster cloud revenue growth in this year’s first quarter than did Amazon.

Northern Virginia has seen the snowball effect of data centers’ clustering tendencies play out more than most other regions around the world. Hyper-scale cloud companies have all flocked to the region in recent years to take advantage of all the interconnection opportunities there, and data center developers have been racing to build in the region to satisfy the demand.

“Our performance testing shows 25%--85% reductions in RTT latency when serving customers in Washington DC, New York, Boston, Montreal, and Toronto compared to using our Iowa or South Carolina regions.”

The Alphabet subsidiary has been spending billions on new cloud data centers to support its enterprise business as it races to bulk up the list of physical infrastructure locations it can offer customers. Urs Hölzle, the company’s senior VP for technical infrastructure, said in March that it had been investing about $10 billion in capital annually on this infrastructure push.

Google launched three availability zones in Northern Virginia, which means three data centers, each with its own physical infrastructure (although not necessarily in three separate buildings). Google usually launches multiple data centers within a region, each hosting a separate availability zone for intra-regional redundancy. Some regions launch with two zones, but the goal is to eventually have at least three per region.

Northern Virginia is Google’s fourth availability region in the US and seventh worldwide. The company has announced plans to launch cloud data centers in Montreal, California, and São Paulo, as well as four European regions, and three in Asia Pacific.